This invention relates to a fluid coupler comprising male and female coupler members.
A fluid coupler comprises a female coupler member and a male coupler member adapted to be inserted into and detachably connected to the female coupler member. The male and female coupler members are securely connected to each other by engagement of locking balls provided in the female coupler member with an annular locking ball receiving recess formed on an exterior surface of the male coupler member. To insert the male coupler member into the female coupler member, an operator needs to shift a locking ball confining sleeve provided on the female coupler member, which has confined the locking balls to a position in which the locking balls partly project into a male coupler receiving hole of the female coupler member for engagement with the locking ball receiving recess, against a spring force to a position where the sleeve allows the locking balls to be moved radially outwardly by the male coupler member.
There is another type of fluid coupler in which a locking ball confining sleeve of a female coupler member has a slanted or conical interior surface for engaging with locking balls. The sleeve is urged by a spring to a position where the slanted or conical interior surface engages with locking balls and positions them at a recess engaging position where the locking balls engage with a locking ball receiving recess of a male coupler member. An operator can insert the male coupler member into the female coupler member by simply pushing the former into the latter so that the locking ball confining sleeve is shifted by a force applied by the male coupler member to the slanted or conical interior surface through the locking balls with the spring being compressed. When the male coupler member is completely inserted into the female coupler member, the locking ball confining sleeve is returned by the spring to an initial position where the slanted or conical interior surface confines the locking balls in the locking ball receiving recess. However, this type of fluid coupler involves a problem in that the male coupler member may be accidentally disconnected from the female coupler member. Namely, if a large pulling force is (accidentally) applied to the male coupler member, a locking ball is urged by the male coupler member against the slanted or conical interior surface of the sleeve and moves or displaces the locking ball confining sleeve from its locking ball confining position.
To solve this problem, another type of fluid coupler has been developed wherein a cylindrical support member is provided inside a female coupler member such that the cylindrical support member is urged to a position where the cylindrical support member supports locking balls to prevent the locking balls from projecting into a male coupler member receiving hole, thereby allowing a male coupler member to be inserted into the female coupler member. When the male coupler member is inserted into the female coupler member, the male coupler member pushes the cylindrical support member rearwards and, when the male coupler member has been completely inserted into the female coupler member, a locking ball receiving recess of the male coupler member is radially aligned with the locking balls, whereby a locking ball confining sleeve is shifted by under a spring force to its locking ball confining position, so that the locking balls are moved radially inwardly into and confined in the locking ball receiving recess by the locking ball confining sleeve. While this type of fluid coupler solves a problem of accidental disconnection, it involves another problem; namely, its size, i.e., since the cylindrical support member is provided inside the female coupler member, a size of the female coupler member must be made relatively large as compared with other types of fluid couplers mentioned above.